Automatic circuit controller



July 1, 1941. NELLES 2,248,010

AUTOMATIC CIRCUIT CONTROLLER I Filed March 9, 19:59

Patented July 1, 1941 AUTOMATIC CIRCUIT CONTROLLER Russell E. Nelles,South Orange, N. J assignor to The Union Manufacturing Company,

New

Britain, Conn., a corporation of Connecticut Application March -9, 1939,Serial No. 260,769

2 Claims.

My invention relates to the class of devices that are employed forcontrolling the conditions of electric circuits and an object of myinvention among others is to produce an apparatus for such purpose thatis simple in construction and particularly effective in operation tosecure the results for which it is designed.

One form of an apparatus embodying my invention and in the constructionand use of which the objects herein set out, as well as others, may beattained, is illustrated in the accompanying drawing in which- Figure 1is a view in side elevationof my improved circuit controller.

Figure 2 is a view on enlarged scale in central vertical section of saidcontroller.

Figure 3 is a view in cross section on a plane denoted by the dottedline 3-3 of Figure 2.

Figure 4 is a view in cross section on a plane denoted by the dottedline 4-4 of Fig. 2.

Figure 5 is an isometric perspective view of the controller supportingframe and parts mounted thereon.

In the drawing herein I have shown a portion only of a hoistingapparatus in connection with which my invention finds ready adaptationand have confined the illustration to so much only as is necessary forits full understanding, all of the parts comprising the invention,however, be-

ing shown. It will be understood, however, that the invention may beapplied in various cases where the making and/or breaking of an electriccircuit is required and its use is not therefore to be limited for anyparticular purpose. In the accompanying drawing the numerals 5 and 6denote supports for a housing comprising part of a hoisting apparatusand which commonly encloses hoisting mechanism, which apparatus may besuspended underneath and carried by a trolley arrangement movable alonga track depending from overhead, in a manner common to such structuresand which will therefore be readily understood by those skilled in theart. A shaft 1 is rotatably mounted in the supports 5 and 6 and ballbearings 8 may be employed for this purpose if desired. A hoisting drum9 is secured to the shaft 1 to be rotated thereby, and power may beapplied to the shaft to rotate it by a motor of any desired form andcommon to structures of this type, this matter of driving beingimmaterial to my invention. However, for the purpose of the description,I have shown a gear In secured to the drum or shaft and affording a partof the driving connection between the motor and the shaft.

A hole II is bored into one end "of the shaft and is threaded to receivethe threaded shank l2 of a switch actuating head l3 mounted forreciprocating movement in a switch supporting frame l4 secured to thesupport 6 in any suitable manner, screw bolts being shown herein forthis purpose, the switch actuating head l3 which is of insulatingmaterial extending into said frame, as shown in Fig. 5. This frame isopen from side to side and comprises ends |5-l6 with top and bottom bars11 and I8 joined to and connecting said ends, as shown in Fig. 2.Contactor block guides in the form of guide'rods I9 are each secured atone end to and project from the frame end I5, the opposite ends of saidguides being supported in the end l6. Contactor blocks 2-ll--2I aremounted for adjustable sliding movement on said guide rods, as shown inFig. '5, these blocks being composed of any suitable insulatingmaterial. They are split as at 22 between the holes through which theguide rods extend, and clamp bolts 23 extend through each block andacross said slot-s as a means for retaining the blocks in place afterthey have been adjusted in proper positions. These contactor blocks 20and 2| have contacts 24 and 25, respectively, secured as by means ofbinding screws 26 each of which passes through the contactor block towhich it is attached, the heads of-these screws serving for theattachment of a conducting wire to be hereinafter described. Thecontacts 24 and 25 are fixed and coact with spring contacts 21 and 28secured, respectively, to the conductor blocks 20 and '21. These springcontacts are preferably of 'U -shape with their free ends positioned totouch the contacts '24 and 25, the opposite ends of the spring contactsbeing secured to the contactor blocks by means of screws as shown inFig. 5, these screws, as 29, serving as binding screws for a wire to behereinafter described.

The switch actuating head 13 has a guide pin 3B which travels in a guidegroove 3! in the bar I8, as shown in Fig. 2, this to prevent the headfrom turning. Said head [3 also has a switch actuating pin 32 projectingfrom one side of the head to press against the spring contacts 21 28 forthe purpose of breaking the circuit between the contacts 2 i25 and thespring contacts 2128.

The electrical circuits for operating the device may be arranged invarious ways to suit fancy or convenience or any particular condition,such arrangement not being material to my invention. One arrangementwhich will satisfactorily answer the purpose is diagrammaticallyillustrated 2 of the drawing in which the light ,linesdenote thecontrolling circuit and the heavy of the cable (not shown) dependingfrom the" carrier upon which this limit switch is mounted, the switch atthe end of the cable being located in position for ready access by theoperator in charge of the apparatus and in a manner well known to thoseskilled in the art. This switch 36 has a main contact 31 and two branchcontacts, with a switch member 40' pivotally attached at the contact 31and having swinging movement to engage either of the branch contacts 38or 33. The switch member 40 may be operated in any well known manner asby either of the two push buttons, successive pressures upon each ofwhich will cause said member to be engaged with and disengaged from oneof the contacts 38 or 39.

Branch wires 4|42 extend from the branch contacts 33-49 to the bindingscrews 26 on the blocks and 2|, and return wires 4344 extend from thebinding screws 29 to electrically operated switch actuating devices4546, and from thence to the main line wire 34.

It will of course be understood that current passes from the wires 4|and 42, to the binding screws 26, to the contacts 24-25, and from thenceto the spring'contacts 21--28, and from thence to the binding screws 29,and from thence to the return wires 43-44.

The actuating devices 45-46 may be of any well known type whereby whenelectrified by current passing through them, they will operate to throwswitches now to be described for controlling the power circuit foroperating the drum 9. It is not thought necessary to describe in detailthese switch operating devices as they may be constructed in diiferentways that will readily suggest themselves to electricians skilled inthis art.

The power circuit for operating the drum 9 comprises two independentcircuits each of which is connected with a power wire 41 or 48, theformer extending from the main line wire 34 and the latter extendingfrom the main line wire 33. For convenience of description the circuiton the left of Fig. 2 will be termed the up circuit as it will operateto rotate the motor 52 in a direction to turn the drum 9, to wind up thecable 49 on the drum and thereby raise the load suspended by said cable,and the, circuit on the right will be termed the down circuit as it willeffect rotation of the drum 9 in a direction to unwind said 'cable andtherefore lower the load suspended therefrom.

Each'of these circuits includes a three-pole switch, although othertypes of switches may be employed. These switches 50-5! when closed willeffect rotation of the drum 9. For example, the push button, not shownbut represented by the switch 36 and connected with the switch actuatingdevice 45, being operated to excite said device, the up switch 50 willbe closed and the electric current will be caused to pass through thearmature of themotor 52 in one direction, thereby effecting rotation'ofthe drum 9 in a certain direction. Upon second operation of the pushbutton just mentioned the switch actuating device 45 will cease toreceive current and the switch will thereupon be opened in a manner wellknown, as by means of springs. Operation of the other push buttonhereinbefore mentioned will effect operation of the down switch 46 in,

is sufiicient for a clear understanding a brief description of one willanswer for both. The wire 41 which is general to both the up and downcircuits transmits current to the wire 53 connected with a contact ofthe switch blade on the left of the set 50 of blades and from thence thecurrent passes along wire 54, field of motor 55, wire 56 to the centerblade of said set 50, of blades, along said blade and wire 51 to thearmature of the motor 52, through said motor and along wires 58 and 59to the blade on the left of said set 50 and by said blade and along wire48 to the main line 33, thus completing the air:- cuit.

The down circuit may be traced in substantially the same manner exceptthat the current passes by wire 60 connected with the center blade ofthe set 5| of blades and also with wire 58 to the opposite side of thearmature of the motor from that above described with reference to the upcircuit, thereby operating said motor in a direction reverse to thatbefore described and operating to rotate the drum to unwind the cableand lower its load. I

As a means for protecting the switch or make and break mechanism ahousing 6| is secured to one of the supports 6 as shown in Figs. 1 and 2of'the drawing. An important feature of the invention resides in a meansfor lubricating the threaded shank on the switch actuating head, thisconsisting of a duct or oil hole 52 extending axially within the shaft 1of the drum and opening into the threaded hole I I, said duct extendingfrom any oil opening conveniently located within the drum and shaft.

While the pin 32 is insulated by insertion in the insulated head 13 itis obvious that this result may be obtained by forming the head or pin,either or both, of insulating material.

In accordance with the provisions of the patent statutes I havedescribed the principles of operation of my invention, together with thedevice which I now consider to represent the best embodiment thereof;but I desire to have it understood that the device shown is onlyillustrative and that the invention may be carried out by other meansand applied to uses other than those above set out.

I claim: I

1. In a limit switch construction of the character described, anon-rotatable supporting member, a rotatable member having a threadedsocket therein journaled in said supporting member, a shaft threaded insaid socket with a switch actuating head on the projecting end thereof,a'mcmber rigidly mounted in said supporting member and wherein saidrigidly mounted member includes a substantially rectangular frame withthe switch actuating head located within said frame and wherein thereare cooperative means including a pin carried by the switch actuatinghead extending into a slotted opening formed in one side of saidrectangular frame.

2. In a limit switch construction of the character described, anon-rotatable supporting memher, a rotatable member having a threadedsocket therein journaled in said supporting member, a shaft threaded insaid socket with a switch actuating head on the projecting end thereof,a member rigidly mounted in said supporting member and wherein saidrigidly mounted member includes a substantially rectangular frame withthe switch actuating head located within said frame and wherein thereare cooperative means including a pin carried by the switch actuatinghead extending into a slotted opening formed in one side of saidrectangular frame, and means supported in opposite ends of said frameupon which said pairs of contacts are mounted.

RUSSELL E. NELLES.

